The US president's chief science adviser says the nation's current efforts to tackle climate change are insufficient in the long-term.

Speaking to BBC News at the American Association for the Advancement of Science (AAAS) meeting in Washington DC, Professor John Holdren said the current US Congress was unlikely to pass new legislation to put a price on CO2 emissions. He said that over the first two years of President Obama's administration, "We didn't get as much done as the President had hoped for" in respect to the issue of climate change.

Professor Holdren faces a more sceptical Congress than he would like, and one that proposes a series of congressional hearings to assess the science of climate change.

"Bring it on" should be the Democrats' response to the new House Republican majority's pledge to hold investigatory hearings on the Obama Administration's environmental policies.

If Republicans want to use an open forum to debunk human-induced global warming and challenge the legitimacy and wisdom of the executive branch to regulate greenhouse gases, go right ahead. Their partisan zeal could very well trigger an embarrassing public backlash.

Democrats should welcome the opportunity for expert witnesses to testify in behalf of the necessity to curb global warming as well as the specific need for the Environmental Protection Agency (EPA) to limit industrial greenhouse gas emissions. There are articulate environmental scientists (and the Democratic minority will make sure they are on the witness list if the GOP majority won't) who can present in laymen's terms with persuasive documentation the case for President Obama's "green" strategy. These experts need to come to the hearings not just to deliver a positive message with clarity. Under the glare of television cameras, they must be prepared to directly dismantle any global warming deniers' claims advanced at the session, and do so unsolicited if need be.

All the Republican demagoguery in the world won't break down witnesses who know their stuff, have the skills to communicate it in a simple, straightforward way, and possess the temperament not to be rattled by heavy-handed, derisive interrogation.

The American Geophysical Union plans to announce Monday that 700 researchers have agreed to speak out on the issue. The effort is a pushback against congressional conservatives who have vowed to kill regulations on greenhouse gas emissions.

Reporting from Washington — Faced with rising political attacks, hundreds of climate scientists are joining a broad campaign to push back against congressional conservatives who have threatened prominent researchers with investigations and vowed to kill regulations to rein in man-made greenhouse gas emissions.

The still-evolving efforts reveal a shift among climate scientists, many of whom have traditionally stayed out of politics and avoided the news media. Many now say they are willing to go toe-to-toe with their critics, some of whom gained new power after the Republicans won control of the House in last Tuesday's election.

On Monday, the American Geophysical Union, the country's largest association of climate scientists, plans to announce that 700 climate scientists have agreed to speak out as experts on questions about global warming and the role of man-made air pollution.

Some are prepared to go before what they consider potentially hostile audiences on conservative talk-radio and television shows.

Professor John Beddington dismisses 'unreasonable' comments from groups including Nigel Lawson's thinktank, as Royal Society responds to critics with new climate science guide.

The government's chief scientific adviser has hit out at climate sceptics who attack global warming science on spurious grounds.

The statements from Professor John Beddington appeared to be a veiled attack on the former Tory chancellor and arch climate sceptic Nigel Lawson.

Beddington said that he had met Lord Lawson to brief him about the science of global warming.

His comments came as the Royal Society announced that it would publish a new guide to climate science for the public following criticism of existing statements on the topic, reportedly from 43 of the society's 1,489 fellows.

"It has been suggested that the society holds the view that anyone challenging the consensus on climate change is malicious – this is ridiculous," said Professor Martin Rees, the society's president.

"Science is organised scepticism and the consensus must shift in light of the evidence.

"In the current environment we believe this new guide will be very timely. Lots of people are asking questions, indeed even within the fellowship of the society there are differing views."

One of the key scientists at the center of the Climategate email scandal has threatened suit against the creators of a video parodying the event. Lawyers for Dr. Michael Mann of Penn State University say the video “irreparably harms Dr. Mann’s personal and professional reputation.”

The video, launched last November in the wake of the scandal that saw some of the top climate scientists’ emails exposed, uses an image of Mann taken from Penn State’s website. Singing the refrain “Hide the Decline” which refers to one of the more controversial emails, the video is set to the tune of "Draggin the Line" by Tommy James and the Shondells.

Originally created by the operators of the website Minnesotans for Global Warming (M4GW), the video became a YouTube sensation and garnered over half a million views in five months.

In a letter from the lawfirm Cozen – O’Connor Attorneys, Peter Fontaine demands that all versions of the video be pulled from YouTube and other sites. Fontaine writes that, “The referenced video clearly defames Professor Mann by leaving viewers with the incorrect impression that he falsified data to generate desired results in connection with his research activities.”

The proper channels have failed. It's time for mass civil disobedience to cut off the financial oxygen from denial and skepticism.

If you're one of those who believe that this is not just necessary but also possible, speak to us. Let's talk about what that mass civil disobedience is going to look like.

If you're one of those who have spent their lives undermining progressive climate legislation, bankrolling junk science, fueling spurious debates around false solutions, and cattle-prodding democratically-elected governments into submission, then hear this:

The climate secretary, Ed Miliband, last night warned of the danger of a public backlash against the science of global warming in the face of continuing claims that experts have manipulated data.

In an exclusive interview with the Observer, Miliband spoke out for the first time about last month's revelations that climate scientists had withheld and covered up information and the apology made by the influential UN climate body, the Intergovernmental Panel on Climate Change (IPCC), which admitted it had exaggerated claims about the melting of Himalayan glaciers.

The perceived failure of global talks on combating climate change in Copenhagen last month has also been blamed for undermining public support. But in the government's first high-level recognition of the growing pressure on public opinion, Miliband declared a "battle" against the "siren voices" who denied global warming was real or caused by humans, or that there was a need to cut carbon emissions to tackle it.

"It's right that there's rigour applied to all the reports about climate change, but I think it would be wrong that when a mistake is made it's somehow used to undermine the overwhelming picture that's there," he said.

"We know there's a physical effect of carbon dioxide in the atmosphere leading to higher temperatures, that's a question of physics; we know CO2 concentrations are at their highest for 6,000 years; we know there are observed increases in temperatures; and we know there are observed effects that point to the existence of human-made climate change. That's what the vast majority of scientists tell us."

Mistakes and attempts to hide contradictory data had to be seen in the light of the thousands of pages of evidence in the IPCC's four-volume report in 2007, said Miliband. The most recent accusation about the panel's work is that its chairman, Rajendra Pachauri, may have known before the Copenhagen summit that its assessment report had seriously exaggerated the rate of melting of the Himalayan glaciers.

However, Miliband was adamant that the IPCC was on the right track. "It's worth saying that no doubt when the next report comes out it will suggest there have been areas where things have been happening more dramatically than the 2007 report implied," he said.

The danger of climate scepticism was that it would undermine public support for unpopular decisions needed to curb carbon emissions, including the likelihood of higher energy bills for households, and issues such as the visual impact of wind turbines, said Miliband, who is also energy secretary.